Benjamin Farjeon is said to have been born on 12 May 1838 in London, England, to Dinah Levy and her husband, Jacob Farjeon, who ran a second-hand clothing business. As one of perhaps five children in a poor Jewish family, he received little formal education. His first job was as a printer's devil on the Nonconformist, a Christian newspaper, where he became a skilled compositor. After a breach with his father over religious matters, he left England in 1854 for the goldfields of Victoria, taking steerage passage to Melbourne on the Ocean Wave. During the voyage he produced several copies of a handwritten newspaper, the Ocean Record.
Farjeon spent a month working as an accountant in Melbourne; then he set out for the goldfields, moving from camp to camp and starting newspapers at each one. In 1861, anxious to reach the new goldfields of Otago as soon as possible, he approached the editor of the Melbourne Argus and sought a position as the paper's New Zealand correspondent.
Arriving in Dunedin he joined the staff of the weekly newspaper the Colonist but soon transferred to the newly established Otago Daily Times where Julius Vogel was editor and joint proprietor with William Cutten. Farjeon was appointed the Times's business manager and also acted as sub-editor, contributor and frequently compositor. In November 1864 Cutten terminated his partnership with Vogel, who took on Farjeon as his partner instead. In March 1866 Farjeon and Vogel sold the Times on condition they were kept on as manager and editor respectively.
Farjeon soon became a well-known figure in Dunedin, involving himself in the social life of the town, and supporting charitable causes such as the Otago Benevolent Institution. He was an early supporter of the Princess Theatre and a founder member and treasurer of the Garrick Club. He bought land and in 1865 and 1866 joined Vogel in a number of speculative mining ventures in Otago.
Farjeon's literary career flourished in Dunedin. His unfinished novel, The life and adventures of Christopher Congleton, appeared anonymously in serial form in the Otago Witness during 1862 and 1863. Shadows on the snow (1865) and Grif: a story of colonial life (1866) appeared next, under the name he was to use as an author: Benjamin Leopold Farjeon. Both works, which were illustrated by Nicholas Chevalier (a long-standing friend of the Farjeon family) and published by William Hay, drew on Farjeon's experience of the Australian goldfields. They were, in part, simultaneously composed and set up in type by Farjeon in the Times office. Grif made Farjeon's name as a novelist and was later revised and several times reprinted. Two further novels, Jessie Trim and At the sign of the silver flagon, and a story, 'Jackass Flat', were published in Dunedin papers between 1874 and 1880, after Farjeon's return to London.
Farjeon also met with considerable success as a dramatist and producer of his own plays at the Princess Theatre. Three satirical burlesques, The golden fleece, or the loves of Jason and Medea (1864), Faust (1865) and Guy Fawkes (1867), were played to great acclaim. He also produced a highly coloured three-act drama, A life's revenge (1864), set in revolutionary France and loosely based on Wilkie Collins's story 'Sister Rose'.
In a brief memoir of Farjeon, Sir George Fenwick described him as 'of the quick, alert, restless type, of rather short stature, with beady black eyes'. His daughter, Eleanor, saw him as exuberant, impetuous and extravagant. 'His mood (when it wasn't irascible) was overflowingly generous.'
His impulsive nature is illustrated by the circumstances which led to his departure from New Zealand in December 1867. Farjeon had dedicated Shadows on the snow to Charles Dickens and sent him a copy in the hope that Dickens would publish it in his weekly periodical, All the Year Round. On the basis of Dickens's mildly encouraging reply – he declined Shadows – Farjeon threw up a burgeoning career in Dunedin and returned to England.
Farjeon settled in London and adopted a literary lifestyle with enthusiasm, becoming widely known as a prolific and popular author. His output included sentimental Christmas stories such as Blade-o'-grass (1871); three-decker novels (many with working class settings) such as Joshua Marvel (1871) and The duchess of Rosemary Lane (1876); and sensational fiction of which the best-known examples are Great Porter Square: a mystery (1884) and The mystery of M. Felix (1890).
On 6 June 1877 at the Register Office, Hampstead, Farjeon married Margaret Jane Jefferson. The couple had four sons (one of whom died in infancy) and a daughter, Eleanor Farjeon, the children's author. Benjamin Leopold Farjeon died at Hampstead on 23 July 1903.